INSULATED PIPES ABOVE THE GROUND

Rule of thumb for the required power in normal cases:

Required power 10 W/m pipe:

– if the pipe diameter is max. 50 mm
– if the insulation is min 50 mm mineral wool
– the lowest ambient temperature is -30°C

In other cases the required power is calculated as per below:

P/m = 2 x π x dt x k x S / In (dy / di)

P/m	=	required power in W/m
dt	=	The difference in temperature in °C. (the lowest permitted temperature of the medium minus the lowest frequent ambient temperature).
k	=	The permeability of the insulation material in W/m°C (J/m°C x 1.16) For mineral wool 0.046 W/m°C
S	=	Safety factor, is put to 1.3 -1.7 depending how it is exposed to weather and wind.
dy	=	The interior diameter of the insulation in mm.
di	=	The outer diameter of the pipe in mm.